[NTLK] Can the Newton's ARM processor ever be upgraded?

[Matthias Melcher]

> On 26. Nov 2025, at 19:09, Doug <ispinn at gmail.com> wrote:
> 
> I seem to remember reading detailed paper explaining why the processor
> cannot be upgraded due to timing issues. I searched but couldn't find it.
> 
> If it's hogtied due to speed limitations on other parts of its components,
> then can multiple sets of old technology be replaced with their
> contemporary and speed-enhanced equivalents?
> Doug

The StrongARM was pretty much custom made for Apple. Acorn and DEC were able to throw it together very quickly fo Apple who then changed the entire design of the MP. The internal coprocessor was geared toward Apple's requirements.

You can increase the internal speed of the system by a few percent, but that also increments the speed of the serial port. But you can't use a different CPU because it will not have the same internal peripherals.

The SA-110 had a successor, the SA-1110(*). I downloaded the specs, and they integrated pretty much everything that Apple had solved with external custom chips. The SA-1110 had a PCMCIA controller on board, LCD output drivers, serial ports, and so on.

The SA-1110 does not replace the SA-110 though, The internal registers for the periphery is completely different. No big deal if you have the ROM source code. But if you don't there is chance. 

This is quite similar to what happens if we were to find a different device with an ARM32 CPU. The ROM would run, but it would try to talk to peripherals that are simply not there. Apple had the very nice foresight to create a driver system, so licensees of ROM could add theri own drivers for their own peripherals, but as we know, all development was halted before that came into play much, so there is neither documentation nor a true separation for completely independent ROMs.

(*)

Likely DEC was hoping to sell the SA-1110 to the MessagePad that would surely come after the MP2100. But Palm was going with a Motorola m86k, and Windows Mobile devices used Intel, as Microsoft was and still is attached to Intel at the hip. DEC had to give the StrongARM development to Intel a year or two later as part of a settlement. Intel the sold ARM in 2004 to cut cost.